Apparatus and method for utilizing a meniscus in substrate processing

ABSTRACT

A method for processing a substrate is provided. The method includes applying an active agent to an active region of a surface of the substrate. Then, the method includes generating a fluid meniscus on the surface of the substrate with a proximity head, where the fluid meniscus is surrounding the active region. In one example, processing the surface of the substrate with the active agent includes one of an etching operation, a cleaning operation, a rinsing operation, a plating operation, or a lithography operation, and processing the surface of the substrate with the fluid meniscus includes one of an etching operation, a cleaning operation, a rinsing operation, a plating operation, a drying operation, or a lithography operation.

CROSS REFERENCE To RELATED APPLICATION

This application is a divisional application of U.S. patent applicationSer. No. 10/956,799, filed on Sep. 30, 2004 from which priority under 35U.S.C. § 120 is claimed, entitled “Apparatus and Method for Utilizing AMeniscus in Substrate Processing which is a continuation-in-part of U.S.patent application Ser. No. 10/883,301, filed on Jun. 30, 2004 fromwhich priority under 35 U.S.C. § 120 is claimed, entitled “ConcentricProximity Processing Head” which is a continuation-in-part of U.S.patent application Ser. No. 10/404,692, filed on Mar. 31, 2003, fromwhich priority under 35 U.S.C. § 120 is claimed, entitled “Methods andSystems for Processing a Substrate Using a Dynamic Liquid Meniscus”which is a continuation-in-part of U.S. patent application Ser. No.10/330,843 filed on Dec. 24, 2002 and entitled “Meniscus, Vacuum, IPAVapor, Drying Manifold,” which is a continuation-in-part of U.S. patentapplication Ser. No. 10/261,839 filed on Sep. 30, 2002 and entitled“Method and Apparatus for Drying Semiconductor Wafer Surfaces Using aPlurality of Inlets and Outlets Held in Close Proximity to the WaferSurfaces.” The aforementioned patent applications are herebyincorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to semiconductor wafer processing and,more particularly, to apparatuses and techniques for more efficientlyapplying and removing fluids from wafer surfaces while reducingcontamination and decreasing wafer processing costs.

2. Description of the Related Art

In the semiconductor chip fabrication process, it is well-known thatthere is a need to process a wafer using operations such as cleaning anddrying. In each of these types of operations, there is a need toeffectively apply and remove fluids for the wafer operation process.

For example, wafer cleaning may have to be conducted where a fabricationoperation has been performed that leaves unwanted residues on thesurfaces of wafers. Examples of such a fabrication operation includeplasma etching (e.g., tungsten etch back (WEB)) and chemical mechanicalpolishing (CMP). In CMP, a wafer is placed in a holder which pushes awafer surface against a rolling conveyor belt. This conveyor belt uses aslurry which consists of chemicals and abrasive materials to cause thepolishing. Unfortunately, this process tends to leave an accumulation ofslurry particles and residues at the wafer surface. If left on thewafer, the unwanted residual material and particles may cause, amongother things, defects such as scratches on the wafer surface andinappropriate interactions between metallization features. In somecases, such defects may cause devices on the wafer to become inoperable.In order to avoid the undue costs of discarding wafers having inoperabledevices, it is therefore necessary to clean the wafer adequately yetefficiently after fabrication operations that leave unwanted residues.

After a wafer has been wet cleaned, the wafer must be dried effectivelyto prevent water or cleaning fluid remnants from leaving residues on thewafer. If the cleaning fluid on the wafer surface is allowed toevaporate, as usually happens when droplets form, residues orcontaminants previously dissolved in the cleaning fluid will remain onthe wafer surface after evaporation (e.g., and form water spots). Toprevent evaporation from taking place, the cleaning fluid must beremoved as quickly as possible without the formation of droplets on thewafer surface. In an attempt to accomplish this, one of severaldifferent drying techniques are employed such as spin drying, IPA, orMarangoni drying. All of these drying techniques utilize some form of amoving liquid/gas interface on a wafer surface which, if properlymaintained, results in drying of a wafer surface without the formationof droplets. Unfortunately, if the moving liquid/gas interface breaksdown, as often happens with all of the aforementioned drying methods,droplets form and evaporation occurs resulting in contaminants beingleft on the wafer surface. The most prevalent drying technique usedtoday is spin rinse drying (SRD).

FIG. 1A illustrates movement of fluids on a wafer 10 during an SRDprocess. In this drying process, a wet wafer is rotated at a high rateby rotation 14. In SRD, by use of centrifugal force, the fluid used torinse the wafer is pulled from the center of the wafer to the outside ofthe wafer and finally off of the wafer as shown by fluid directionalarrows 16. As the fluid is being pulled off of the wafer, a movingliquid/gas interface 12 is created at the center of the wafer and movesto the outside of the wafer (i.e., the circle produced by the movingliquid/gas interface 12 gets larger) as the drying process progresses.In the example of FIG. 1A, the inside area of the circle formed by themoving liquid/gas interface 12 is free from the fluid and the outsidearea of the circle formed by the moving liquid/gas interface 12 is thefluid. Therefore, as the drying process continues, the section inside(the dry area) of the moving liquid/gas interface 12 increases while thearea (the wet area) outside of the moving liquid/gas interface 12decreases. As stated previously, if the moving liquid/gas interface 12breaks down, droplets of the fluid form on the wafer and contaminationmay occur due to evaporation of the droplets. As such, it is imperativethat droplet formation and the subsequent evaporation be limited to keepcontaminants off of the wafer surface. Unfortunately, the present dryingmethods are only partially successful at the prevention of moving liquidinterface breakdown.

In addition, the SRD process has difficulties with drying wafer surfacesthat are hydrophobic. Hydrophobic wafer surfaces can be difficult to drybecause such surfaces repel water and water based (aqueous) cleaningsolutions. Therefore, as the drying process continues and the cleaningfluid is pulled away from the wafer surface, the remaining cleaningfluid (if aqueous based) will be repelled by the wafer surface. As aresult, the aqueous cleaning fluid will want the least amount of area tobe in contact with the hydrophobic wafer surface. Additionally, theaqueous cleaning solution tends cling to itself as a result of surfacetension (i.e., as a result of molecular hydrogen bonding). Therefore,because of the hydrophobic interactions and the surface tension, balls(or droplets) of aqueous cleaning fluid forms in an uncontrolled manneron the hydrophobic wafer surface. This formation of droplets results inthe harmful evaporation and the contamination discussed previously. Thelimitations of the SRD are particularly severe at the center of thewafer, where centrifugal force acting on the droplets is the smallest.Consequently, although the SRD process is presently the most common wayof wafer drying, this method can have difficulties reducing formation ofcleaning fluid droplets on the wafer surface especially when used onhydrophobic wafer surfaces. Certain portion of the wafer may havedifferent hydrophobic properties.

FIG. 1B illustrates an exemplary wafer drying process 18. In thisexample a portion 20 of the wafer 10 has a hydrophilic area and aportion 22 has a hydrophobic area. The portion 20 attracts water so afluid 26 pools in that area. The portion 22 is hydrophobic so that arearepels water and therefore there can be a thinner film of water on thatportion of the wafer 10. Therefore, the hydrophobic portions of thewafer 10 often dry more quickly than the hydrophilic portions. This maylead to inconsistent wafer drying that can increase contamination levelsand therefore decrease wafer production yields.

Therefore, there is a need for a method and an apparatus that avoids theprior art by enabling optimized fluid management and application to awafer that reduces contaminating deposits on the wafer surface. Suchdeposits as often occurs today reduce the yield of acceptable wafers andincrease the cost of manufacturing semiconductor wafers.

SUMMARY OF THE INVENTION

Broadly speaking, the present invention fills these needs by providing asubstrate processing apparatus that is capable of processing wafersurfaces with an active cavity within a fluid meniscus. In addition,proximity heads generating a fluid meniscus by using self regulation arealso provided. It should be appreciated that the present invention canbe implemented in numerous ways, including as a process, an apparatus, asystem, a device or a method. Several inventive embodiments of thepresent invention are described below.

In one embodiment, an apparatus for processing a substrate is providedwhich includes a proximity head proximate to a surface of the substratewhen in operation. The apparatus also includes an opening on a surfaceof the proximity head to a cavity defined in the proximity head wherethe cavity delivers an active agent to the surface of the substratethrough the opening. The apparatus further includes a plurality ofconduits on the surface of the proximity head that generates a fluidmeniscus on the surface of the substrate surrounding the opening.

In another embodiment, a method for processing a substrate is providedwhich includes applying an active agent to an active region of a surfaceof the substrate and generating a fluid meniscus on the surface of thesubstrate with a proximity head where the fluid meniscus surrounds theactive region.

In yet another embodiment, a method for processing a substrate isprovided which includes generating a first fluid meniscus on a surfaceof the substrate and generating a second fluid meniscus on the surfaceof the substrate where the second fluid meniscus is adjacent to thefirst fluid meniscus. The generating the first fluid meniscus and thesecond fluid meniscus includes siphoning at least the first fluid fromthe first fluid meniscus.

In another embodiment, a method for processing substrate is providedwhich includes applying a fluid onto a surface of a substrate andsiphoning at least the fluid from the surface of the substrate where theremoving being processed just as the fluid is applied to the surface ofthe substrate. The applying and the removing form a fluid meniscus.

In yet another embodiment, a proximity head for processing a substrateis provided which includes at least one first conduit defined within theproximity head where the at least one first conduit applies a fluid to asurface of the substrate. The proximity head includes at least onesecond conduit defined within the proximity head where the at least onesecond conduit is in close proximity to the at least one first conduitwhere the at least one second conduit siphons the fluid from the surfaceof the wafer. The application of the fluid to the surface of thesubstrate and siphoning of the fluid from the surface of the substrategenerates a fluid meniscus.

The advantages of the present invention are numerous. Most notably, theapparatuses and methods described herein utilize a proximity head withat least one cavity. By using the cavity to apply active agents to thewafer surface, the wafer surface may be processed and then the meniscussurrounding the active cavity may rinse the processed regions.Therefore, the process environment can be powerfully controlled andmanaged thereby generating more consistent wafer processing.Consequently, wafer processing and production may be increased andhigher wafer yields may be achieved due to efficient wafer processing.

In addition, the proximity head described herein may utilize siphon toremove fluid from the fluid meniscus. By utilizing a siphon, meniscusstability and control may be enhanced because the meniscus in such anembodiment may be self regulating. When the flow of fluid into themeniscus is high the siphon removes fluid at a higher rate.Consequently, wafer processing may be made consistent thereby increasingwafer processing yields.

Other aspects and advantages of the present invention will becomeapparent from the following detailed description, taken in conjunctionwith the accompanying drawings, illustrating by way of example theprinciples of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be readily understood by the followingdetailed description in conjunction with the accompanying drawings. Tofacilitate this description, like reference numerals designate likestructural elements.

FIG. 1A illustrates movement of cleaning fluids on a wafer during an SRDdrying process.

FIG. 1B illustrates an exemplary wafer drying process.

FIG. 2 shows a wafer processing system in accordance with one embodimentof the present invention.

FIG. 3 illustrates a proximity head performing a wafer processingoperation in accordance with one embodiment of the present invention.

FIG. 4A illustrates a wafer processing operation that may be conductedby a proximity head in accordance with one embodiment of the presentinvention.

FIG. 4B illustrates a side view of exemplary proximity heads for use ina dual wafer surface processing system in accordance with one embodimentof the present invention.

FIG. 5A shows a multi-menisci proximity head in accordance with onembodiment of the present invention.

FIG. 5B shows a cross section view of the multi-menisci proximity headin accordance with one embodiment of the present invention.

FIG. 6A illustrates a multi-menisci proximity head in accordance withone embodiment of the present invention.

FIG. 6B illustrates the processing surface of the proximity head inaccordance with one embodiment of the present invention.

FIG. 6C shows a closer view of the processing surface of themulti-meniscus proximity head in accordance with one embodiment of thepresent invention.

FIG. 6D shows the facilities plate attaching to the body to form themulti-menisci proximity head in accordance with one embodiment of thepresent invention.

FIG. 6E illustrates a cross section view of the proximity head inaccordance with one embodiment of the present invention.

FIG. 7 illustrates a cross-sectional view of the multi-menisci proximityhead in exemplary wafer processing operations in accordance with oneembodiment of the present invention.

FIG. 8 illustrates a siphoning system in accordance with one embodimentof the present invention.

FIG. 9 illustrates a proximity head with an active cavity in accordancewith one embodiment of the present invention.

FIG. 10 shows a cross section of the proximity head in operation inaccordance with one embodiment of the present invention.

FIG. 11 shows a longitudinal view of the proximity head in accordancewith one embodiment of the present invention.

FIG. 12 shows a cross sectional view of a proximity head with the activecavity window in accordance with one embodiment of the presentinvention.

FIG. 13 illustrates a cross sectional view of a proximity head whichincludes multiple cavities with multiple menisci in one embodiment ofthe present invention.

FIG. 14A shows a cross shaped proximity head in accordance with oneembodiment of the present invention.

FIG. 14B illustrates a circular shaped proximity head in accordance withone embodiment of the present invention.

FIG. 14C shows an oval shaped proximity head in accordance with oneembodiment of the present invention.

FIG. 14D illustrates a strip shaped proximity head in accordance withone embodiment of the present invention.

FIG. 14E shows a wedge shaped proximity head in accordance with oneembodiment of the present invention.

FIG. 15A shows an exemplary view of a processing surface of theproximity head in accordance with one embodiment of the presentinvention.

FIG. 15B illustrates an exemplary view of a processing surface of theproximity head in accordance with one embodiment of the presentinvention.

DETAILED DESCRIPTION

An invention for methods and apparatuses for processing a substrate isdisclosed. In the following description, numerous specific details areset forth in order to provide a thorough understanding of the presentinvention. It will be understood, however, by one of ordinary skill inthe art, that the present invention may be practiced without some or allof these specific details. In other instances, well known processoperations have not been described in detail in order not tounnecessarily obscure the present invention.

While this invention has been described in terms of several preferableembodiments, it will be appreciated that those skilled in the art uponreading the preceding specifications and studying the drawings willrealize various alterations, additions, permutations and equivalentsthereof. It is therefore intended that the present invention includesall such alterations, additions, permutations, and equivalents as fallwithin the true spirit and scope of the invention.

The figures below illustrate embodiments of an exemplary waferprocessing system using proximity heads to generate any suitable shape,size, and location of the fluid meniscus(es). In one embodiment, theproximity head utilizes siphon to remove fluid(s) from the fluidmeniscus. In another embodiment, the proximity head includes an activecavity that is surrounded by a fluid meniscus thereby generating aprocessing region that is highly controllable. In one embodiment, theregion, after processing, can be processed using another waferprocessing operation (e.g., rinsing) very soon after the initialprocessing of the region by the active cavity because the fluid meniscussurrounds the active cavity. This technology may be utilized to performany suitable type of combination of types of wafer operation(s) such as,for example drying, etching, plating, etc.

It should be appreciated that the systems and proximity heads asdescribed herein are exemplary in nature, and that any other suitabletypes of configurations that would enable the generation and movement ofa meniscus or enable a meniscus with a cavity enclosed therein may beutilized. In the embodiments shown, the proximity head(s) may move in alinear fashion from a center portion of the wafer to the edge of thewafer. It should be appreciated that other embodiments may be utilizedwhere the proximity head(s) move in a linear fashion from one edge ofthe wafer to another diametrically opposite edge of the wafer, or othernon-linear movements may be utilized such as, for example, in a radialmotion, in a circular motion, in a spiral motion, in a zig-zag motion,in a random motion, etc. In addition, the motion may also be anysuitable specified motion profile as desired by a user. In addition, inone embodiment, the wafer may be rotated and the proximity head moved ina linear fashion so the proximity head may process all portions of thewafer. It should also be understood that other embodiments may beutilized where the wafer is not rotated but the proximity head isconfigured to move over the wafer in a fashion that enables processingof all portions of the wafer. In other embodiments, either or both ofthe wafer and the proximity head do not move depending on the waferprocessing operation and the configuration of the proximity head. Infurther embodiments, the proximity head may be held stationary and thewafer may be moved to be processed by the fluid meniscus. As with theproximity head, the wafer may move in any suitable motion as long as thedesired wafer processing operation is accomplished.

In addition, the proximity head and the wafer processing system asdescribed herein may be utilized to process any shape and size ofsubstrates such as for example, 200 mm wafers, 300 mm wafers, flatpanels, etc. Moreover, the size of the proximity head and in turn thesizes of the menisci may vary. In one embodiment, the size of theproximity head and the sizes of the menisci may be larger than a waferbeing processed, and in another embodiment, the proximity head and thesizes of the menisci may be smaller than the wafer being processed.Furthermore, the menisci as discussed herein may be utilized with otherforms of wafer processing technologies such as, for example, brushing,lithography, megasonics, etc.

A fluid meniscus can be supported and moved (e.g., onto, off of andacross a wafer) with a proximity head. Various proximity heads andmethods of using the proximity heads are described in co-owned U.S.patent application Ser. No. 10/834,548 filed on Apr. 28, 2004 andentitled “Apparatus and Method for Providing a Confined Liquid forImmersion Lithography,” which is a continuation in part of U.S. patentapplication Ser. No. 10/606,022, filed on Jun. 24, 2003 and entitled“System And Method For Integrating In-Situ Metrology Within A WaferProcess” which is a continuation-in-part of U.S. patent application Ser.No. 10/330,843 filed on Dec. 24, 2002 and entitled “Meniscus, Vacuum,IPA Vapor, Drying Manifold,” which is a continuation-in-part of U.S.patent application Ser. No. 10/261,839 filed on Sep. 30, 2002 andentitled “Method and Apparatus for Drying Semiconductor Wafer SurfacesUsing a Plurality of Inlets and Outlets Held in Close Proximity to theWafer Surfaces,” both of which are incorporated herein by reference inits entirety. Additional embodiments and uses of the proximity head arealso disclosed in U.S. patent application Ser. No. 10/330,897, filed onDec. 24, 2002, entitled “System for Substrate Processing with Meniscus,Vacuum, IPA vapor, Drying Manifold” and U.S. patent application Ser. No.10/404,692, filed on Mar. 31, 2003, entitled “Methods and Systems forProcessing a Substrate Using a Dynamic Liquid Meniscus.” Stilladditional embodiments of the proximity head are described in U.S.patent application Ser. No. 10/404,270, filed on Mar. 31, 2003, entitled“Vertical Proximity Processor,” U.S. patent application Ser. No.10/603,427, filed on Jun. 24, 2003, and entitled “Methods and Systemsfor Processing a Bevel Edge of a Substrate Using a Dynamic LiquidMeniscus,” U.S. patent application Ser. No. 10/606,022, filed on Jun.24, 2003, and entitled “System and Method for Integrating In-SituMetrology within a Wafer Process,” U.S. patent application Ser. No.10/607,611 filed on Jun. 27, 2003 entitled “Apparatus and Method forDepositing and Planarizing Thin Films of Semiconductor Wafers,” U.S.patent application Ser. No. 10/611,140 filed on Jun. 30, 2003 entitled“Method and Apparatus for Cleaning a Substrate Using Megasonic Power,”U.S. patent application Ser. No. 10/817,398 filed on Apr. 1, 2004entitled “Controls of Ambient Environment During Wafer Drying UsingProximity Head,” U.S. patent application Ser. No. 10/817,355 filed onApr. 1, 2004 entitled “Substrate Proximity Processing Structures andMethods for Using and Making the Same,” U.S. patent application Ser. No.10/817,620 filed on Apr. 1, 2004 entitled “Substrate Meniscus Interfaceand Methods for Operation,” U.S. patent application Ser. No. 10/817,133filed on Apr. 1, 2004 entitled “Proximity Meniscus Manifold,” U.S. Pat.No. 6,488,040, issued on Dec. 3, 2002, entitled “Capillary ProximityHeads For Single Wafer Cleaning And Drying,” U.S. Pat. No. 6,616,772,issued on Sep. 9, 2003, entitled “Methods For Wafer Proximity CleaningAnd Drying,” and U.S. patent application Ser. No. 10/742,303 entitled“Proximity Brush Unit Apparatus and Method.” Additional embodiments anduses of the proximity head are further described in U.S. patentapplication Ser. No. 10/883,301 entitled “Concentric ProximityProcessing Head,” and U.S. patent application Ser. No. 10/882,835entitled “Method and Apparatus for Processing Wafer Surfaces Using Thin,High Velocity Fluid Layer.” The aforementioned patent applications arehereby incorporated by reference in their entirety.

It should be appreciated that the system described herein is justexemplary in nature, and the proximity head described herein may be usedin any suitable system such as, for example, those described in theUnited States Patent Applications referenced above. It should also beappreciated that FIGS. 2 through 8 describe formation of a meniscuswhich may use a siphon to remove fluid from the wafer surface andtherefore process variables (e.g. flow rates, dimensions, etc.)described therein may be different than the process variables describedfor a proximity head with an active cavity as described in FIG. 9through 15B. It should also be appreciated that the siphoning may beapplied to any suitable proximity head described herein.

FIG. 2 shows a wafer processing system 100 in accordance with oneembodiment of the present invention. The system 100 includes rollers 102a and 102 b which may hold and/or rotate a wafer to enable wafersurfaces to be processed. The system 100 also includes proximity heads106 a and 106 b that, in one embodiment, are attached to an upper arm104 a and to a lower arm 104 b respectively. In one embodiment, theproximity heads 106 a and/or 106 b may be any suitable proximity headsas described in further detail in reference to FIGS. 2 through 15described herein. As described herein the term “multi-menisci proximityhead” is a proximity head capable of generating one or more fluidmenisci. In a one embodiment, a first fluid meniscus is substantiallysurrounded by a second fluid meniscus. In one, the first fluid meniscusand the second fluid meniscus are concentric with the second fluidmeniscus surrounding the first fluid meniscus. The proximity head may beany suitable apparatus that may generate a fluid meniscus as describedherein and described in the patent application incorporated by referenceabove. The upper arm 104 a and the lower arm 104 b can be part of anassembly which enables substantially linear movement (or in anotherembodiment a slight arc-like movement) of the proximity heads 106 a and106 b along a radius of the wafer. In yet another embodiment, theassembly may move the proximity heads 106 a and 106 b in any suitableuser defined movement.

In one embodiment the arms 104 are configured to hold the proximity head106 a above the wafer and the proximity head 106 b below the wafer inclose proximity to the wafer. For example, in one exemplary embodimentthis may be accomplished by having the upper arm 104 a and the lower arm104 b be movable in a vertical manner so once the proximity heads aremoved horizontally into a location to start wafer processing, theproximity heads 106 a and 106 b can be moved vertically to a position inclose proximity to the wafer. In another embodiment, the upper arm 104 aand the lower arm 104 b may be configured to start the proximity heads106 a and 106 b in a position where the menisci are generated beforeprocessing and the menisci that has already been generated between theproximity heads 106 a and 106 b may be moved onto the wafer surface tobe processed from an edge area of a wafer 108. Therefore, the upper arm104 a and the lower arm 104 b may be configured in any suitable way sothe proximity heads 106 a and 106 b can be moved to enable waferprocessing as described herein. It should also be appreciated that thesystem 100 may be configured in any suitable manner as long as theproximity head(s) may be moved in close proximity to the wafer togenerate and control multiple meniscus that, in one embodiment, areconcentric with each other. It should also be understood that closeproximity may be any suitable distance from the wafer as long as amenisci may be maintained. In one embodiment, the proximity heads 106 aand 106 b (as well as any other proximity head described herein) mayeach be located between about 0.1 mm to about 10 mm from the wafer togenerate the fluid menisci on the wafer surface. In a preferableembodiment, the proximity heads 106 a and 106 b (as well as any otherproximity head described herein) may each be located bout 0.5 mm toabout 2.0 mm from the wafer to generate the fluid menisci on the wafersurface, and in more preferable embodiment, the proximity heads 106 aand 106 b (as well as any other proximity head described herein) may belocated about 1.5 mm from the wafer to generate the fluid menisci on thewafer surface.

In one embodiment, the system 100, the arms 104 are configured to enablethe proximity heads 106 a and 106 b to be moved from processed tounprocessed portions of the wafer. It should be appreciated that thearms 104 may be movable in any suitable manner that would enablemovement of the proximity heads 106 a and 106 b to process the wafer asdesired. In one embodiment, the arms 104 may be motivated by a motor tomove the proximity head 106 a and 106 b along the surface of the wafer.It should be understood that although the wafer processing system 100 isshown with the proximity heads 106 a and 106 b, that any suitable numberof proximity heads may be utilized such as, for example, 1, 2, 3, 4, 5,6, etc. The proximity heads 106 a and/or 106 b of the wafer processingsystem 100 may also be any suitable size or shape as shown by, forexample, any of the proximity heads as described herein. The differentconfigurations described herein generate the fluid menisci between theproximity head and the wafer. The fluid menisci may be moved across thewafer to process the wafer by applying fluid to the wafer surface andremoving fluids from the surface. In such a way, depending on the fluidsapplied to the wafer, cleaning, drying, etching, and/or plating may beaccomplished. In addition, the first fluid meniscus may conduct one typeof operation and the second fluid meniscus that at least partiallysurrounds the first fluid meniscus may conduct the same operation or adifferent wafer processing operation as the first fluid meniscus.Therefore, the proximity heads 106 a and 106 b can have any numeroustypes of configurations as shown herein or other configurations thatenable the processes described herein. It should also be appreciatedthat the system 100 may process one surface of the wafer or both the topsurface and the bottom surface of the wafer.

In addition, besides processing the top and/or bottom surfaces of thewafer, the system 100 may also be configured to process one side of thewafer with one type of process (e.g., etching, cleaning, drying,plating, etc.) and process the other side of the wafer using the sameprocess or a different type of process by inputting and outputtingdifferent types of fluids or by using a different configuration menisci.The proximity heads can also be configured to process the bevel edge ofthe wafer in addition to processing the top and/or bottom of the wafer.This can be accomplished by moving the menisci off (or onto) the edgethe wafer which processes the bevel edge. It should also be understoodthat the proximity heads 106 a and 106 b may be the same type ofapparatus or different types of proximity heads.

The wafer 108 may be held and rotated by the rollers 102 a and 102 b inany suitable orientation as long as the orientation enables a desiredproximity head to be in close proximity to a portion of the wafer 108that is to be processed. In one embodiment, the rollers 102 a and 102 bcan rotate in a clockwise direction to rotate the wafer 108 in acounterclockwise direction. It should be understood that the rollers maybe rotated in either a clockwise or a counterclockwise directiondepending on the wafer rotation desired. In one embodiment, the rotationimparted on the wafer 108 by the rollers 102 a and 102 b serves to movea wafer area that has not been processed into close proximity to theproximity heads 106 a and 106 b. However, the rotation itself does notdry the wafer or move fluid on the wafer surfaces towards the edge ofthe wafer. Therefore, in an exemplary wafer processing operation, theunprocessed areas of the wafer would be presented to the proximity heads106 a and 106 b through both the linear motion of the proximity heads106 a and 106 b and through the rotation of the wafer 108. The waferprocessing operation itself may be conducted by at least one of theproximity heads. Consequently, in one embodiment, processed portions ofthe wafer 108 would expand from a center region to the edge region ofthe wafer 108 in a spiral movement as the processing operationprogresses. In another embodiment, when the proximity heads 106 a and106 b are moved from the periphery of the wafer 108 to the center of thewafer 108, the processed portions of the wafer 108 would expand from theedge region of the wafer 108 to the center region of the wafer 108 in aspiral movement.

In an exemplary processing operation, it should be understood that theproximity heads 106 a and 106 b may be configured to dry, clean, etch,and/or plate the wafer 108. In an exemplary drying embodiment, the atleast one of first inlet may be configured to input deionized water(DIW) (also known as a DIW inlet), the at least one of a second inletmay be configured to input N₂ carrier gas containing isopropyl alcohol(IPA) in vapor form (also known as IPA inlet), and the at least oneoutlet may be configured to remove fluids from a region between thewafer and a particular proximity head. It should be appreciated that theremoval of fluids may be accomplished by any suitable method wherebyfluid is removed in an efficient manner consistent with themethodologies described herein. In one embodiment, vacuum may be appliedthrough the at least one outlet (also known as vacuum outlet). Inanother embodiment, where the at least one outlet removes substantiallysingle phase fluids (e.g., mostly liquid), then a method such as siphonmay be utilized. Siphoning of fluid through the at least one outlet isdescribed in further detail in reference to FIG. 8. It should beappreciated that although EPA vapor is used in some of the exemplaryembodiments, any other type of vapor may be utilized such as forexample, nitrogen, any suitable alcohol vapor, organic compounds,volatile chemicals, etc. that may be miscible with water.

In an exemplary cleaning embodiment, a cleaning solution may besubstituted for the DIW. An exemplary etching embodiment may beconducted where an etchant may be substituted for the DIW. In anadditional embodiment, plating may be accomplished as described infurther detail in reference to U.S. patent application Ser. No.10/607,611 filed on Jun. 27, 2003 entitled “Apparatus and Method forDepositing and Planarizing Thin Films of Semiconductor Wafers” which wasincorporated by reference above. In addition, other types of solutionsmay be inputted into the first inlet and the second inlet depending onthe processing operation desired.

It should be appreciated that the inlets and outlets located on a faceof the proximity head may be in any suitable configuration as long asstable menisci as described herein may be utilized. In one embodiment,the at least one N₂/IPA vapor inlet may be adjacent to the at least onevacuum outlet which is in turn adjacent to the at least one processingfluid inlet to form an IPA-vacuum-processing fluid orientation. Such aconfiguration can generate an outside meniscus that at least partiallysurrounds the inside meniscus. In addition, the inside meniscus may begenerated through a configuration with a processing fluid-vacuumorientation. Therefore, one exemplary embodiment where a second fluidmeniscus at least partially surrounds a first fluid meniscus may begenerated by an IPA-vacuum-second processing fluid-vacuum-firstprocessing fluid-vacuum-second processing fluid-vacuum-IPA orientationas described in further detail below. It should be appreciated thatother types of orientation combinations such as IPA-processingfluid-vacuum, processing fluid-vacuum-IPA, vacuum-IPA-processing fluid,etc. may be utilized depending on the wafer processes desired and whattype of wafer processing mechanism is sought to be enhanced. In oneembodiment, the IPA-vacuum-processing fluid orientation may be utilizedto intelligently and powerfully generate, control, and move the meniscilocated between a proximity head and a wafer to process wafers. Theprocessing fluid inlets, the N₂/IPA vapor inlets, and the vacuum outletsmay be arranged in any suitable manner if the above orientation ismaintained. For example, in addition to the N₂/IPA vapor inlet, thevacuum outlet, and the processing fluid inlet, in an additionalembodiment, there may be additional sets of IPA vapor outlets,processing fluid inlets and/or vacuum outlets depending on theconfiguration of the proximity head desired. It should be appreciatedthat the exact configuration of the inlet and outlet orientation may bevaried depending on the application. For example, the distance betweenthe IPA input, vacuum, and processing fluid inlet locations may bevaried so the distances are consistent or so the distances areinconsistent. In addition, the distances between the IPA input, vacuum,and processing fluid outlet may differ in magnitude depending on thesize, shape, and configuration of the proximity head 106 a and thedesired size of a process menisci (i.e., menisci shape and size). Inaddition, exemplary IPA-vacuum-processing fluid orientation may be foundas described in the United States patent applications referenced above.It should be appreciated that anywhere vacuum is utilized to removefluid from the wafer surface, siphoning as described in further detailin reference to FIG. 8 may be utilized for substantially single phasefluids.

In one embodiment, the proximity heads 106 a and 106 b may be positionedin close proximity to a top surface and a bottom surface respectively ofthe wafer 108 and may utilize the EPA and DIW inlets and a vacuumoutlets as described herein to generate wafer processing menisci incontact with the wafer 108 which are capable of processing the topsurface and the bottom surface of the wafer 108. The wafer processingmenisci may be generated in a manner consistent with the descriptions inreference to Applications referenced and incorporated by referenceabove. At substantially the same time the IPA and the processing fluidis inputted, a vacuum may be applied in close proximity to the wafersurface to remove the IPA vapor, the processing fluid, and/or the fluidsthat may be on the wafer surface. It should be appreciated that althoughIPA is utilized in the exemplary embodiment, any other suitable type ofvapor may be utilized such as for example, nitrogen, any suitablealcohol vapor, organic compounds, hexanol, ethyl glycol, acetone, etc.that may be miscible with water. These fluids may also be known assurface tension reducing fluids. The portion of the processing fluidthat is in the region between the proximity head and the wafer is themenisci. It should be appreciated that as used herein, the term “output”can refer to the removal of fluid from a region between the wafer 108and a particular proximity head, and the term “input” can be theintroduction of fluid to the region between the wafer 108 and theparticular proximity head. In another embodiment, the proximity heads106 a and 106 b may be scanned over the- wafer 108 while being moved atthe end of an arm that is being moved in a slight arc.

FIG. 3 illustrates a proximity head 106 performing a wafer processingoperation in accordance with one embodiment of the present invention.FIGS. 3 through 4B show a method of generating a basic fluid meniscuswhile FIGS. 5A through 15B discuss apparatuses and methods forgenerating a more complex menisci configuration. The proximity head 106,in one embodiment, moves while in close proximity to a top surface 108 aof the wafer 108 to conduct a wafer processing operation. It should beappreciated that the proximity head 106 may also be utilized to process(e.g., clean, dry, plate, etch, etc.) a bottom surface 108 b of thewafer 108. In one embodiment, the wafer 108 is rotating so the proximityhead 106 may be moved in a linear fashion along the head motion whilethe top surface 108 a is being processed. By applying the IPA 310through the inlet 302, the vacuum 312 through outlet 304, and theprocessing fluid 314 through the inlet 306, the meniscus 116 may begenerated. It should be appreciated that the orientation of theinlets/outlets as shown in FIG. 3 is only exemplary in nature, and thatany suitable inlets/outlets orientation that may produce a stable fluidmeniscus may be utilized such as those configurations as described inthe United States patent applications incorporated by referencepreviously.

FIG. 4A illustrates a wafer processing operation that may be conductedby a proximity head 106 a in accordance with one embodiment of thepresent invention. Although FIG. 4A shows a top surface 108 a beingprocessed, it should be appreciated that the wafer processing may beaccomplished in substantially the same way for the bottom surface 108 bof the wafer 108. In one embodiment, the inlet 302 may be utilized toapply isopropyl alcohol (IPA) vapor toward a top surface 108 a of thewafer 108, and the inlet 306 may be utilized to apply a processing fluidtoward the top surface 108 a of the wafer 108. In addition, the outlet304 may be utilized to apply vacuum to a region in close proximity tothe wafer surface to remove fluid or vapor that may located on or nearthe top surface 108 a. As described above, it should be appreciated thatany suitable combination of inlets and outlets may be utilized as longas the meniscus 116 may be formed. The IPA may be in any suitable formsuch as, for example, IPA vapor where EPA in vapor form is inputtedthrough use of a N₂ gas. Moreover, any suitable fluid used forprocessing the wafer (e.g., cleaning fluid, drying fluid, etching fluid,plating fluid, etc.) may be utilized that may enable or enhance thewafer processing. In one embodiment, an IPA inflow 310 is providedthrough the inlet 302, a vacuum 312 may be applied through the outlet304 and processing fluid inflow 314 may be provided through the inlet306. Consequently, if a fluid film resides on the wafer 108, a firstfluid pressure may be applied to the wafer surface by the IPA inflow310, a second fluid pressure may be applied to the wafer surface by theprocessing fluid inflow 314, and a third fluid pressure may be appliedby the vacuum 312 to remove the processing fluid, IPA and the fluid filmon the wafer surface.

Therefore, in one embodiment of a wafer processing, as the processingfluid inflow 314 and the EPA inflow 310 is applied toward a wafersurface, fluid (if any) on the wafer surface is intermixed with theprocessing inflow 314. At this time, the processing fluid inflow 314that is applied toward the wafer surface encounters the IPA inflow 310.The EPA forms an interface 118 (also known as an IPA/processing fluidinterface 118) with the processing fluid inflow 314 and along with thevacuum 312 assists in the removal of the processing fluid inflow 314along with any other fluid from the surface of the wafer 108. In oneembodiment, the IPA/processing fluid interface 118 reduces the surfaceof tension of the processing fluid. In operation, the processing fluidis applied toward the wafer surface and almost immediately removed alongwith fluid on the wafer surface by the vacuum applied by the outlet 304.The processing that is applied toward the wafer surface and for a momentresides in the region between a proximity head and the wafer surfacealong with any fluid on the wafer surface forms a meniscus 116 where theborders of the meniscus 116 are the IPA/processing fluid interfaces 118.Therefore, the meniscus 116 is a constant flow of fluid being appliedtoward the surface and being removed at substantially the same time withany fluid on the wafer surface. The nearly immediate removal of theprocessing fluid from the wafer surface prevents the formation of fluiddroplets on the region of the wafer surface being dried thereby reducingthe possibility of contamination on the wafer 108 after the processingfluid has accomplished its purpose depending on the operation (e.g.,etching, cleaning, drying, plating, etc.). The pressure (which is causedby the flow rate of the EPA) of the downward injection of IPA also helpscontain the meniscus 116.

The flow rate of the N2 carrier gas containing the IPA may assist incausing a shift or a push of processing fluid flow out of the regionbetween the proximity head and the wafer surface and into the outlets304 (vacuum outlets) through which the fluids may be outputted from theproximity head. It is noted that the push of processing fluid flow isnot a process requirement but can be used to optimize meniscus boundarycontrol. Therefore, as the IPA and the processing fluid are pulled intothe outlets 304, the boundary making up the IPA/processing fluidinterface 118 is not a continuous boundary because gas (e.g., air) isbeing pulled into the outlets 304 along with the fluids. In oneembodiment, as the vacuum from the outlets 304 pulls the processingfluid, IPA, and the fluid on the wafer surface, the flow into theoutlets 304 is discontinuous. This flow discontinuity is analogous tofluid and gas being pulled up through a straw when a vacuum is exertedon combination of fluid and gas. Consequently, as the proximity head 106a moves, the meniscus moves along with the proximity head, and theregion previously occupied by the meniscus has been dried due to themovement of the EPA/processing fluid interface 118. It should also beunderstood that the any suitable number of inlets 302, outlets 304 andinlets 306 may be utilized depending on the configuration of theapparatus and the meniscus size and shape desired. In anotherembodiment, the liquid flow rates and the vacuum flow rates are suchthat the total liquid flow into the vacuum outlet is continuous, so nogas flows into the vacuum outlet.

It should be appreciated any suitable flow rate may be utilized for theN₂/IPA, processing fluid, and vacuum as long as the meniscus 116 can bemaintained. In one embodiment, the flow rate of the processing fluidthrough a set of the inlets 306 is between about 25 ml per minute toabout 3,000 ml per minute. In a preferable embodiment, the flow rate ofthe processing fluid through the set of the inlets 306 is about 800 mlper minute. It should be understood that the flow rate of fluids mayvary depending on the size of the proximity head. In one embodiment alarger head may have a greater rate of fluid flow than smaller proximityheads. This may occur because larger proximity heads, in one embodiment,have more inlets 302 and 306 and outlets 304.

In one embodiment, the flow rate of the N₂/IPA vapor through a set ofthe inlets 302 is between about 1 liters per minute (SLPM) to about 100SLPM. In a preferable embodiment, the IPA flow rate is between about 6and 20 SLPM.

In one embodiment, the flow rate for the vacuum through a set of theoutlets 304 is between about 10 standard cubic feet per hour (SCFH) toabout 1250 SCFH. In a preferable embodiment, the flow rate for a vacuumthough the set of the outlets 304 is about 350 SCFH. In an exemplaryembodiment, a flow meter may be utilized to measure the flow rate of theN₂/IPA, processing fluid, and the vacuum.

It should be appreciated that any suitable type of wafer processingoperation may be conducted using the meniscus depending on theprocessing fluid utilized. For example, a cleaning fluid such as, forexample, SC-1, SC-2, etc., may be used for the processing fluid togenerate wafer cleaning operation. In a similar fashion, differentfluids may be utilized and similar inlet and outlet configurations maybe utilized so the wafer processing meniscus may also etch and/or platethe wafer. In one embodiment, etching fluids such as, for example, HF,EKC proprietary solution, KOH etc., may be utilized to etch the wafer.In another embodiment, plating fluids such as, for example, Cu Sulfate,Au Chloride, Ag Sulfate, etc. in conjunction with electrical input maybe conducted.

FIG. 4B illustrates a side view of exemplary proximity heads 106 a and106 b for use in a dual wafer surface processing system in accordancewith one embodiment of the present invention. In this embodiment, byusage of inlets 302 and 306 to input N₂/IPA and processing fluidrespectively along with the outlet 304 to provide a vacuum, the meniscus116 may be generated. In addition, on the side of the inlet 306 oppositethat of the inlet 302, there may be a outlet 304 to remove processingfluid and to keep the meniscus 116 intact. As discussed above, in oneembodiment, the inlets 302 and 306 may be utilized for IPA inflow 310and processing fluid inflow 314 respectively while the outlet 304 may beutilized to apply vacuum 312. In addition, in yet more embodiments, theproximity heads 106 a and 106 b may be of a configuration as shown inthe United States patent applications referenced above. Any suitablesurface coming into contact with the meniscus 116 such as, for example,wafer surfaces 108 a and 108 b of the wafer 108 may be processed by themovement of the meniscus 116 into and away from the surface.

FIGS. 5A through 7 show embodiments of the present invention where afirst fluid meniscus is at least partially surrounded by at least asecond fluid meniscus. It should be appreciated that the first fluidmeniscus and/or the second fluid meniscus may be generated to conductany suitable type of substrate/wafer processing operation such as, forexample, lithography, etching, plating, cleaning, and drying. The firstfluid meniscus and the second fluid meniscus may be any suitable shapeor size depending on the substrate processing operation desired. Incertain embodiments described herein, the first fluid meniscus and thesecond fluid meniscus are concentric where the second fluid meniscussurrounds the first fluid meniscus and the first fluid meniscus and thesecond fluid meniscus provide a continuous fluid connection. Therefore,after the first fluid meniscus processes the substrate, the portion ofthe wafer processed by the first fluid meniscus is immediately processedby the second fluid meniscus without a substantial amount of the contactwith the atmosphere. It should be appreciated that depending on theoperation desired, in one embodiment, the first fluid meniscus maycontact the second meniscus and in another embodiment, the first fluidmeniscus does not directly contact the second meniscus.

FIG. 5A shows a multi-menisci proximity head 106-1 in accordance with onembodiment of the present invention. The multi-menisci proximity head106-1 includes a plurality of source inlets 306 a that can apply a firstfluid to the wafer surface. The first fluid can then be removed from thewafer surface by application of siphon or vacuum through a plurality ofsource outlets 304 a. Therefore, the first fluid meniscus may begenerated by the conduits located within a first fluid meniscus region402 of the processing surface on the multi-menisci proximity head 106-1.

The multi-menisci proximity head 106-1 may also include a plurality ofsource inlets 306 b that can apply a second fluid to the wafer surface.The second fluid can then be removed from the wafer surface byapplication of vacuum through a plurality of source outlets 304 b. Inone embodiment, a portion of the second fluid is also removed by theplurality of source outlets 304 a in conjunction with the removal of thefirst fluid. In one embodiment, the plurality of source outlets 304 amay be called a one phase fluid removal conduit because the outlets 304a remove liquids applied to the wafer through the source inlets 306 aand 306 b. In such one phase removal, siphoning and/or vacuum may beutilized. When siphoning is used, the meniscus may be self regulatedbecause as more fluid is applied to the wafer surface, the more thefluid is removed from the wafer surface through siphon. Therefore, evenat variable flow rates, the siphoning can increase or decrease fluidremoval rate depending on the flow rates into the fluid meniscus(es).Siphoning with regard to single phase fluid removal from the wafersurface (e.g., from the meniscus(es) on the wafer surface) is describedin further detail in reference to FIG. 8.

In addition, the plurality of source outlets 306 b may be called a twophase removal conduit because the outlets 304 b removes the second fluidfrom the source inlets 304 b and the atmosphere outside of the fluidmeniscus. Therefore, in one embodiment, the outlets 304 b removes bothliquid and gas while the outlets 304 a remove only liquids. As a result,the second fluid meniscus may be created by the conduits located withina second fluid meniscus region 404 of the processing surface on themulti-meniscus proximity head 106-1.

Optionally, the multi-menisci proximity head 106-1 may include aplurality of source inlets 302 which can apply a third fluid to thewafer surface. In one embodiment, the third fluid may be a surfacetension reducing fluid that can reduce the surface tension of aliquid/atmosphere border of the second meniscus formed by thatapplication of the second fluid to the wafer surface.

In addition, the processing surface (e.g., the surface area of themulti-menisci proximity head where the conduits exist) of themulti-menisci proximity head 106-1 (or any other proximity headdiscussed herein) may be of any suitable topography such as, forexample, flat, raised, lowered. In one embodiment, the processingsurface of the multi-menisci 106-1 may have a substantially flatsurface.

FIG. 5B shows a cross section view of the multi-menisci proximity head106-1 in accordance with one embodiment of the present invention. Themulti-menisci proximity head 106-1 can apply the first fluid through theplurality of source inlets 306 a and remove the first fluid through theplurality of source outlets 304 a through use of siphoning and/orvacuum. The first fluid meniscus 116 a is located underneath a regionsubstantially surrounded by the plurality of source outlets 304 a. Themulti-menisci proximity head 106-1 can also apply the second fluidthrough the plurality of source inlets 306 b and remove the second fluidthrough the plurality of source outlets 304 a on one side of the secondfluid meniscus and 304 b on the other side. In one embodiment, theplurality of source inlets 302 may apply the third fluid to decrease thesurface tension of the fluid making up the second fluid meniscus 116 b.The plurality of source inlets 302 may be optionally angled to betterconfine the second fluid meniscus 116 b.

FIG. 6A illustrates a multi-menisci proximity head 106-2 in accordancewith one embodiment of the present invention. The proximity head 106-2includes, in one embodiment, a facilities plate 454 and a body 458. Itshould be appreciated the proximity head 106-2 may include any suitablenumbers and/or types of pieces as long as the first fluid meniscus andthe second fluid meniscus as described herein may be generated. In oneembodiment, the facilities plate 454 and the body 458 may be boltedtogether or in another embodiment, the plate 454 and the body 458 may beattached by an adhesive. The facilities plate 454 and the body 458 maybe made from the same material or different materials depending on theapplications and operations desired by a user.

The proximity head 106-2 may include a processing surface 458 whichincludes conduits where fluid(s) may be applied to surface of the waferand the fluid(s) maybe removed from a surface of the wafer. Theprocessing surface 458 may, in one embodiment, be elevated above asurface 453 as shown by an elevated region 452. It should be appreciatedthat the processing surface 458 does not have to be elevated and thatthe surface 458 may be substantially planar with the surface 453 of theproximity head 106-2 that faces the surface of the wafer beingprocessed.

FIG. 6B illustrates the processing surface 458 of the proximity head106-2 in accordance with one embodiment of the present invention. In oneembodiment, the processing surface 458 is a region of the proximity head106-2 which generates the fluid menisci. The processing surface 458 mayinclude any suitable number and type of conduits so the first fluidmeniscus and the second fluid meniscus may be generated. In oneembodiment, the processing surface 458 includes fluid inlets 306 a,fluid outlets 304 a, fluid inlets 306 b, fluid outlets 304 b, and fluidinlets 302.

The fluid inlets 306 a may apply a first fluid to the surface of thewafer, and the fluid inlets 306 b may apply a second fluid to thesurface of the wafer. In addition, the fluid outlets 304 a may removethe first fluid and a portion of a second fluid from the surface of thewafer by the application of siphoning and/or vacuum, and the fluidoutlets 304 b may remove a portion of the second fluid from the surfaceof the wafer by the application of vacuum, and the fluid inlets 302 mayapply a fluid that can decrease the surface tension of the second fluid.The first fluid and/or the second fluid may be any suitable fluid thatcan facilitate any one of a lithography operation, an etching operation,a plating operation, a cleaning operation, a rinsing operation, and adrying operation.

FIG. 6C shows a closer view of the processing surface 458 of themulti-meniscus proximity head 106-2 in accordance with one embodiment ofthe present invention. In one embodiment, the processing surface 458includes a first fluid meniscus region 402 which includes the fluidinlets 306 a and fluid outlets 304 a. The processing surface 458 alsoincludes a second fluid meniscus region 404 includes the fluid inlets306 b and the fluid outlets 304 b and the fluid inlets 302. Therefore,the first fluid meniscus region 402 can generate the first fluidmeniscus and the second fluid meniscus region 404 can generate thesecond fluid meniscus.

FIG. 6D shows the facilities plate 454 attaching to the body 456 to formthe multi-menisci proximity head 106-2 in accordance with one embodimentof the present invention. Channels corresponding to the fluid inlets 306a, 306 b, and 302 supply fluid from the facilities plate 454 into thebody 456 of the multi-menisci proximity head 106-2, and channelscorresponding to the fluid outlets 304 a and 304 b remove fluid from thebody 456 to the facilities 454. In one embodiment channels 506 a, 504 a,506 b, 504 b, and 502 correspond to the fluid inlets 306 a, fluidoutlets 304 a, fluid inlets 306 b, fluid outlets 304 b, and fluid inlets302.

FIG. 6E illustrates a cross section view of the proximity head 106-2 inaccordance with one embodiment of the present invention. As described inreference to FIG. 6D, channels 506 a, 506 b, and 502 may supply a firstfluid, a second fluid, and a third fluid to fluid inlets 306 a, 306 b,and 302 respectively. In addition, a channel 504 a may remove acombination of the first fluid and the second fluid from the fluidoutlets 304 a through use of siphoning and/or vacuum, and channel 504 bmay remove combination of the second fluid and the third fluid from theoutlets 304 b. In one embodiment, the first fluid is a first processingfluid that can conduct any suitable operation on a wafer surface suchas, for example, etching, lithography, cleaning, rinsing, and drying.The second fluid is a second processing fluid that may or may not be thesame as the first fluid. As with the first fluid, the second fluid maybe any suitable type of processing fluid such as, for example, a fluidthat can facilitate etching, lithography, cleaning, rinsing, and drying.

FIG. 7 illustrates a cross-sectional view of the multi-menisci proximityhead in exemplary wafer processing operations in accordance with oneembodiment of the present invention. Although FIG. 7 shows a top surfaceof the wafer 108 being processed, it should be appreciated by thoseskilled in the art that both a top surface and a bottom surface of thewafer 108 may be concurrently processed by any of the proximity headsdescribed herein on the top surface of the wafer 108 and by any of theproximity heads described herein on the bottom surface of the wafer 108.In one embodiment, a first wafer processing chemistry is applied to thewafer 108 through fluid inlet 306 a. After the first wafer processingchemistry has processed the wafer surface, the first wafer processingchemistry is removed from the wafer surface through the fluid outlet 304a. The first wafer processing fluid may form a first fluid meniscus 116a between the multi-menisci proximity head 106-2 and the wafer 108. Inone embodiment, a second processing fluid such as, for example,deionized water (DIW) is applied to the wafer surface through the fluidinlets 306 b.

As discussed above, the second processing fluid may be any suitablefluid that can accomplish the desired operation on the wafer surface.After the DIW has processed the wafer surface, the DIW is removed fromthe wafer surface through both the source outlets 304 a and 304 b. TheDIW between the multi-menisci proximity head 106-2 and the wafer surfacemay form a second fluid meniscus 116 b.

In one embodiment, a surface tension reducing fluid such as, forexample, isopropyl alcohol vapor in nitrogen gas may optionally beapplied from the source inlet 302 to the wafer surface to keep theliquid/gas border of the second fluid meniscus 116 b stable. In oneembodiment, the second fluid meniscus 116 b can substantially surroundthe first fluid meniscus 116 a. In this way, after the first fluidmeniscus 116 a has processed the wafer surface, the second fluidmeniscus 116 b can nearly immediately begin operating on a portion ofthe wafer surface already processed by the first fluid meniscus 116 a.Therefore, in one embodiment, the second fluid meniscus 116 b forms aconcentric ring around the first fluid meniscus 116 a. It should beappreciated that the first fluid meniscus 116 a may be any suitablegeometric shape such as, a circle, ellipse, square, rectangle,triangular, quadrilateral, etc. The second fluid meniscus 116 b can beconfigured to at least partially surround whatever shape the first fluidmeniscus 116 a may be. It should be appreciated that, as discussedabove, the first fluid meniscus 116 a and/or the second fluid meniscus116 b may utilize any suitable fluid(s) depending on the waferprocessing operation desired.

It should be appreciated that to generate a stable fluid meniscus, anamount of the first fluid inputted into the first fluid meniscus throughthe source inlets 306 a should be substantially equal to the amount ofthe first fluid removed through the source outlets 304 a. The amount ofthe second fluid inputted into the second fluid meniscus through thesource inlets 306 b should be substantially equal to the amount of thesecond fluid removed through the source outlets 304 a and 304 b. In oneembodiment, the flow rates of the fluids are determined by a distance480 the proximity head 106-2 is off of the wafer 108. It should beappreciated that the distance 480 may be any suitable distance as longas the menisci can be maintained and moved in a stable manner. In oneembodiment, the distance 480 may be between 50 microns and 5 mm, and inanother embodiment 0.5 mm to 2.5 mm. Preferably, the distance 480 isbetween about 1 mm and 1.5 mm. In one embodiment, the distance 480 isabout 1.3 mm.

The flow rates of the fluids as shown in FIG. 7 may be any suitable flowrate that can generate the first fluid meniscus and the second fluidmeniscus that substantially surrounds the first meniscus. Depending onthe distinction desired between the first fluid meniscus and the secondfluid meniscus, the flow rates may differ. In one embodiment, sourceinlets 306 a may apply the first fluid at a flow rate of about 600cc/min, source inlets 306 b may apply the second fluid at a flow rate ofabout 900 cc/min, a source outlets 304 a may remove the first fluid andthe second fluid at a flow rate of about 1200 cc/min, and the sourceoutlets 304 b may remove the second fluid and atmosphere (which mayinclude some IPA vapor in N₂ if such a surface tension reducing fluid isbeing applied to the wafer surface) at a flow rate of about 300 cc/min.In one embodiment, the flow rate of fluids through the source outlets304 may equal 2 times the flow rate of fluid through the source inlets306 a. The flow rate of fluid through the source inlets 306 b may beequal to the flow rate through the source inlets 306 a plus 300 cc/min.It should be appreciated by those skilled in the art that specific flowrate relationships of the source inlets 306 a, 306 b and source outlets304 a, 304 b may change depending on the configuration of the processarea and/or the configuration of the proximity heads described herein.

Moreover, by use of siphoning through the source outlets 304 a, theoptimal flow rate is automatically generated thereby creating a selfregulating meniscus where the flow rate of fluid from the meniscus tothe source outlets 304 is automatically adjusted depending on the flowrates through the source inlets 306 a and 306 b. As long as the fluidbeing removed by the source outlets 304 a is substantially single phasethen the siphon can keep operating to self regulate the shape and sizeof the fluid meniscus.

FIG. 8 illustrates a siphoning system 500 in accordance with oneembodiment of the present invention. In one embodiment, siphoning may beused to control fluid removal through the source outlet(s) (e.g., innerreturn flow). In one embodiment, when siphoning is utilized, vacuum isnot utilized therefore, the flow of fluid from the fluid meniscus ismade independent from fluctuations in the clean dry air generating thevacuum in a vacuum tank. This generates enhanced stability of the innerreturn flow which results in greater stability of the overall meniscus.In addition, the meniscus may become self regulating and therefore bemore robust.

In one embodiment, the siphoning system 500 includes at least one siphontube 548 coupled to the proximity head 106. The one or more siphon tubes548 may be coupled to the proximity head 106 to remove fluid from fluidmeniscus(es) generated by the proximity head 106. In one embodiment, thesiphon tubes 548 are connected at the other end to a receiving tank 560where fluids removed from the proximity head 106 may be outputted fromthe siphon tubes 548. In one embodiment, the receiving tank is at alower elevation than the proximity head 106 which promotes the siphoningaction. In one embodiment, the siphoning system 500 is structured so thegravitational force corresponding to the vertical distance 580 is lessthan the gravitational force corresponding to the vertical distance 582.The maximum siphon flow can be regulated by conductance of plumbing fromthe proximity head 106 to the receiving tank 560. Therefore, specificsiphon flow rates can be achieved via the use of flow restrictor 550 inthe line. Fixed restriction of the flow restrictor 550 can thereforeresult in set and forget siphon flow rates. In addition, variablerestrictions of the flow restrictor 550 may be used for tunable controlof the siphon flow. In one embodiment, the flow restrictor 550 may beany suitable device such as, for example, a valve that can control fluidflow.

In one embodiment, a siphon flow can be induced via tank vacuum tocharge a dry line. In one embodiment, the siphon tube 548 may be chargedby applying vacuum and thereby filling the siphon tube 548 with liquidfrom a fluid meniscus generated by the proximity head 106. Once thesiphon tube 548 is filled with liquid, the vacuum may pull the fluid inthe siphon tube 548 to the receiving tank 560. Once the flow has startedthe tank vacuum in the receiving tank 560 may be eliminated and thesiphon action facilitates the fluid flow through the siphon tube 548.

In another embodiment, the restrictor 550 may be a shut-off valve couldbe used to start and stop the flow without assistance of tank vacuum. Ifthe siphon tube 548 is charged (e.g., filled with liquid), opening thevalve starts siphon flow. If the siphon tube 548 is dry, then it couldbe charged first with fluid and then the siphon flow would begin as soonas the valve is opened. Therefore, in one embodiment, siphon flow can beused for all single-phase liquid lines in the system. In addition,siphon flow is operable with air bubbles as long as the line issubstantially filled with liquid.

It should be appreciated that the siphoning system 500 may be utilizedwith any suitable proximity head 106 that has a fluid return system thatremoves a single phase fluid such as liquids.

FIG. 9 illustrates a proximity head 106-3 with an active cavity inaccordance with one embodiment of the present invention. In oneembodiment, the proximity head 106-3 has a cross section that isdescribed in further detail in reference to FIG. 10 and a longitudinalsection that is described in further detail in reference to FIG. 11. Anexemplary processing surface of the proximity head 106-3 is discussed infurther detail in reference to FIG. 15A.

FIG. 10 shows a cross section of the proximity head 106-3 in operationin accordance with one embodiment of the present invention. In oneembodiment, the proximity head 106-3 includes a source inlet 640 into acavity 642. The cavity 642 may be any suitable shape and may take up anysuitable volume within the proximity head 106-3 as long as the activeagent may be inputted into the cavity 642 and the active agent may beapplied to the wafer surface through an opening (e.g., active cavitywindow 624). In one embodiment, the opening to the cavity 642 issubstantially surrounded by the fluid meniscus 116 generated by theapplication of fluid to the wafer surface by the source inlets 306 andby the removal of the fluid from the fluid meniscus 116 by the sourceoutlets 304 a and 304 b. The cavity 642 may be used to deliver activeagents to the wafer surface via the active cavity window 624. It shouldbe appreciated that the active cavity window 624 may be any suitablesize and/or shape depending on the size and shape of the region of thewafer surface desired to be processed. In one embodiment, the activecavity window 624 defines the opening to the cavity 642. The wafersurface within the active cavity window 624 that is processed by theactive agents is known as an active region. The active agent may be anysuitable liquid, gas, vapor, or other form of chemistry (e.g., foam)that can process the wafer. In one embodiment, the active agent mayinclude substances such as, for example, ozone, chelating agents (e.g.,EDTA, etc.), cleaning chemistries (e.g., SCd, SC2, etc.), semi-aqueoussolvents (e.g., ATMI ST-255 and ATMI PT-15 (made by ATMI of Danbury,Conn.), EKC5800™ (made by EKC Technology in Danville, Calif., etc.), HF,etc.). The active agents can be dispensed via the source inlet 640 whichin one embodiment may include nozzles (e.g., flat fan, cone spray,mist/fogger). It should be appreciated that the source inlet 640 may beany suitable type of opening that can transport the active agent intothe cavity 642.

In operation, the active agents may be rinsed or otherwise removed bythe meniscus 116 that surrounds the active cavity window 624. In thismanner, the wafer 108 may be dry in and dry out meaning that the wafermay, in one embodiment, be dry before wafer processing and substantiallydry after wafer processing even though the wafer surface has beentreated by active agents in the active cavity window 624. Therefore, theactive agents can be confined to the cavity within the proximity head106-3.

In one embodiment, ozone (or other oxidizing gas) may be introduced intothe cavity 642 and the wafer surface in the active cavity window 624 iswetted by the meniscus 116 which may be a heated DIW rinse meniscus. Theozone in this case may react with and remove organic material from thewafer surface through the wafer boundary layer. This may be used inoperation such as, for example, strip photoresist operations.

It should be appreciated that the conduit (i.e., outlets and inlets)pattern and proximity head structure utilized in FIG. 10 as well as theother conduit patterns and proximity head structures discussed hereinare only exemplary in nature and that the proximity head discussedherein encompasses any suitable proximity head structure that may beutilized that can generate a fluid meniscus substantially around aregion of the substrate surface where active agents can conductsubstrate processing.

FIG. 11 shows a longitudinal view of the proximity head 106-3 inaccordance with one embodiment of the present invention. As discussedabove in reference to FIG. 10, the proximity head 106-3 include sourceinlets 640 into the cavity 642. In the embodiment shown in FIG. 11, foursource inlets 640 are defined within the longitudinal section of theproximity head 106-3. It should be appreciated that depending on thewafer processing operation desired and the amount of active agentsdesired to be inputted into the cavity 642, any suitable number ofsource inlets 640 may be included in the proximity head 106-3 such as,for, example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc. Also, the proximityhead in the longitudinal view includes source inlets 306 and sourceoutlets 304 a and 304 as well as source inlets 302 for generating thefluid meniscus 116. In one embodiment, the source inlets 306 may apply aprocessing fluid (e.g., rinsing fluid) to the wafer surface. Theprocessing fluid may be removed from the wafer surface by the sourceoutlet 304 a and 304 b. It should be appreciated that source inlet 302is optionally included in the proximity head 106-3 and depending on theproximity head 106-3 configuration, a stable fluid meniscus may begenerated without usage of the source inlets 302. In one embodiment,when the source inlet 302 is utilized, a surface tension reducing fluidmay be applied to the wafer surface and the outer border of the fluidmeniscus 116. Consequently, the fluid meniscus 116 generated surroundsthe active cavity window 624.

FIG. 12 shows a cross sectional view of a proximity head 106-4 with theactive cavity window 624 in accordance with one embodiment of thepresent invention. It should be appreciated that the cross sectionalview shown in FIG. 12 is another embodiment of the cross sectional viewdiscussed above in reference to FIG. 10. In one embodiment, the crosssectional view of the proximity head 106-4 includes a source inlet 640that can input an active agent into the cavity 642. The active agent canthen process an active region of the substrate surface that is definedby the active cavity window 624. In addition, the cross sectional viewof the proximity head 106-4 also includes source inlets 306 and sourceoutlets 304 a, 304 b, and 304 c. In one embodiment, the proximity head106-4 can apply a fluid through the source inlets 306 to the surface ofthe wafer to a region substantially surrounding the active region. Thesource outlets 304 a, 304 b, and 304 c can remove the fluid from thesurface of the wafer substantially surrounding the active region. Thisapplication and removal of fluid may generate the fluid meniscus thatcan substantially surround the active region. In such an embodiment, anactive agent can be applied to process the active region of the wafersurface and afterwards with either one of wafer or proximity headmovement, the fluid meniscus 116 may further process (e.g., clean,rinse, etch, etc.) the wafer surface in the active region.

In the embodiment shown in FIG. 12, the source outlet 304 a may utilizevacuum to remove fluids from the wafer surface. In one embodiment, thesource outlet 304 a may remove the fluid applied by the source inlets304 a as well as the fluids and/or materials remaining from the activeagent processing of the active region of the wafer surface. The sourceoutlet 304 b in this embodiment may be a single phase meniscus removalconduit. In this embodiment, the source outlet 304 b may use vacuumand/or siphoning to remove the fluid making up the fluid meniscus 116.The source outlet 304 c in this embodiment may utilize vacuum to removethe fluid from an outer region of the fluid meniscus 116 to define theoutside border of the fluid meniscus 116.

FIG. 13 illustrates a cross sectional view of a proximity head 106-5which includes multiple cavities with multiple menisci in one embodimentof the present invention. The cross section view of the proximity head106-5 is another embodiment of the cross section view as discussed inreference to FIG. 10. In addition, it should be appreciated that thesource inlets and outlets such as, for example, source inlet 306 b andsource outlets 304 c and 304 d of the cross sectional view may extendinto a z-axis. It should be appreciated that any suitable plumbing ofthe source inlets and outlets may be utilized that can generate thefluid menisci consistent with the methodologies and descriptions herein.In one embodiment, the proximity head 106-5 includes multiple cavities642 a and 642 b. It should be appreciated that the proximity headsdescribed herein may contain any suitable number of cavities such as,for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc. depending on the waferprocessing operation desired. It should be appreciated that the cavities642 a and 642 b may be any suitable shape and may be located in anysuitable place as long as the openings to the cavities may besubstantially surrounded by fluid menisci.

In one embodiment, the proximity head 106-5 can include source inlets304 b to apply fluid to a wafer surface and source outlets 304 c and 304d to remove fluid from the wafer surface to generate a fluid meniscus116 c. The proximity head 106-5 may also include source inlets 306 a andsource outlets 304 a and 304 b may generate the fluid meniscus 116 bsubstantially surrounding the active region defined by the active cavitywindow 624 a. The proximity head 106-5 may further include source inlets306 c and source outlets 304 e and 304 f to generate the fluid meniscus116 b which can substantially surround the active cavity window 624. Inone embodiment, the proximity head 106-5 may apply an active agent intothe cavities 642 a and 642 b from the source inlets 640 a and 640 brespectively. An exemplary processing surface of the proximity head106-5 is discussed in further detail in reference to FIG. 15B.

FIGS. 14A through 14E illustrate exemplary proximity head structures. Itshould be appreciated that the active cavity windows in all of theembodiments are substantially surrounded by conduits that may generate afluid meniscus substantially surrounding the active cavity windows.

FIG. 14A shows a cross shaped proximity head 106-6 in accordance withone embodiment of the present invention. In one embodiment, the activecavity window 624 is in a shape of a cross. In operation, the proximityhead 106-6 may be configured to generate the fluid meniscus 116 aroundthe active cavity window 624.

FIG. 14B illustrates a circular shaped proximity head 106-7 inaccordance with one embodiment of the present invention. In oneembodiment, the active cavity window 624 is a circular shape. Inoperation, the proximity head 106-7 may be configured to generate thefluid meniscus 116 around the active cavity window 624.

FIG. 14C shows an oval shaped proximity head 106-8 in accordance withone embodiment of the present invention. In one embodiment, the activecavity window 624 is an oval shape. In operation, the proximity head106-8 may be configured to generate the fluid meniscus 116 around theactive cavity window 624.

FIG. 14D illustrates a strip shaped proximity head 106-9 in accordancewith one embodiment of the present invention. In one embodiment, theactive cavity window 624 is a strip shape. In operation, the proximityhead 106-9 may be configured to generate the fluid meniscus 116 aroundthe active cavity window 624.

FIG. 14E shows a wedge shaped proximity head 106-10 in accordance withone embodiment of the present invention. In one embodiment, the activecavity window 624 is a wedge shape. In operation, the proximity head106-10 may be configured to generate the fluid meniscus 116 around theactive cavity window 624.

FIG. 15A shows an exemplary view of a processing surface 700 of theproximity head 106-3 in accordance with one embodiment of the presentinvention. In one embodiment, the processing surface 700 includes thecavity 642 as discussed in further detail in reference to FIGS. 10 and11. The processing surface 700 may also include a region 701substantially surrounding the openings to the cavity 642 which mayinclude a plurality of conduits that can generate the fluid meniscus 116such as, for example, source inlets 306 and source outlets 304 a and 304b as discussed in further detail in reference to FIGS. 10 and 11. In oneembodiment, the plurality of conduits may surround the cavity 642.

FIG. 15B illustrates an exemplary view of a processing surface 704 ofthe proximity head 106-5 in accordance with one embodiment of thepresent invention. In one embodiment, the processing surface 704 mayinclude the cavities 642 a and 642 b as discussed in further detail inreference to FIG. 13. In addition, the proximity head 106-5 may alsoinclude regions 702, 706, and 704 which may substantially surround theopening to the cavities. The regions 702, 706, and 704 include aplurality of conduits that can generate the fluid menisci 116 a, 116 c,and 116 b. In one embodiment, the plurality of conduits may includesource inlets 306 a, 306 b, and 306 c as well as source outlets 304 a,304 b, 304 c, 304 d, 304 e, and 304 f as discussed in further detail inreference to FIG. 13.

While this invention has been described in terms of several preferredembodiments, it will be appreciated that those skilled in the art uponreading the preceding specifications and studying the drawings willrealize various alterations, additions, permutations and equivalentsthereof. It is therefore intended that the present invention includesall such alterations, additions, permutations, and equivalents as fallwithin the true spirit and scope of the invention.

1. A method for processing a substrate, comprising: applying an activeagent to an active region of a surface of the substrate; and generatinga fluid meniscus on the surface of the substrate with a proximity head,the fluid meniscus surrounding the active region.
 2. A method forprocessing a substrate as recited in claim 1, further comprising:processing the surface of the substrate with the active agent; andprocessing the surface of substrate with the fluid meniscus.
 3. A methodfor processing a substrate as recited in claim 2, wherein processing thesurface of the substrate with the active agent includes one of anetching operation, a cleaning operation, a rinsing operation, a platingoperation, or a lithography operation.
 4. A method for processing asubstrate as recited in claim 1, wherein processing the surface of thesubstrate with the fluid meniscus includes one of an etching operation,a cleaning operation, a rinsing operation, a plating operation, a dryingoperation, or a lithography operation.
 5. A method for processing asubstrate as recited in claim 2, wherein generating the fluid meniscusincludes applying a fluid to the surface of the substrate through afluid inlet and removing the fluid from the surface of the substratethrough a fluid outlet.
 6. A method for processing a substrate asrecited in claim 5, wherein the fluid is one of a lithographic fluid, anetching fluid, a plating fluid, a cleaning fluid, or a rinsing fluid. 7.A method for processing a substrate as recited in claim 4, whereingenerating the fluid meniscus further includes applying an additionalfluid to the surface of the substrate through an additional inlet, theadditional fluid being a surface tension reducing fluid.
 8. A method forprocessing a substrate as recited in claim 5, wherein removing the fluidincludes siphoning the fluid to a container that is lower in elevationthan the proximity head.
 9. A method for processing a substrate asrecited in claim 1, wherein the active region is defined by an openingon the surface of the substrate, the opening being to a cavity definedwithin the proximity head.